FRAME 2-21.
Solution to
Frame 2-20.
Suppose you had two fractions, one with a denominator of "3" and the
other with a denominator of "4." One method of getting a common
denominator
denominator is to multiply the denominators together. For a problem
with two denominators ("3" and "4"), a common denominator would be
denominator
"12" (3 x 4 = 12 and 4 x 3 = 12).
Finish solving the following problem:
1
1
1
4
1
3
4
?=
?
+
=
X
+
X
=
+
3
4
3
4
4
3
12
12
___________________________________________________________________
FRAME 2-22.
Solution to
Frame 2-21.
Solve this subtraction problem:
4
3 = 4+3
7
5 _ 3
=
+
=
=
6
8
12
12
12
12
___________________________________________________________________
FRAME 2-23.
Solution to
Frame 2-22.
Although multiplying the denominators together will always give you a
common denominator, sometimes a smaller common denominator can
be found. Consider the previous problem? Can you think of a common
5x8 _ 3x6
40-18=
=
=
denominator for 5/6 and 3/8 that is smaller than 48? What number will
6x8 8x6
48
both 6 and 8 divide into and the quotients be whole numbers (no
remainders)?
22
____________
48
Work the problem 5/6 3/8 again using the smaller common
denominator. (Divide the denominator into the common denominator and
multiply the numerator by the quotient.)
___________________________________________________________________
FRAME 2-24.
Solution to
Frame 2-23.
You can add and subtract fractions in the same problem. Just make
sure that each denominator divides evenly into the common denominator.
24
Try this problem.
5x4 _ 3x3
20-9= 11
1 _ 1
1 _ 1 + 1 _ 1
=
=
+
6x4 8x3
24 24
2
3
5
7
9
11
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MD0900
2-9